March 1, 2004 – Students at Stanford, Columbia and Yale universities are allowed to join.

June 1, 2004 – The company moves to Palo Alto, California.

September 1, 2004 – The Facebook Wall is added.

December 1, 2004 – One million users are active on the site.

September 1, 2005 – High school students are allowed to join Facebook.

September 20, 2005 – The company drops “the” from the name and becomes Facebook.

December 1, 2005 – Six million users are active on the site.

April 1, 2006 – Facebook for Mobile launches.

September 5, 2006 – The News Feed is introduced.

September 26, 2006 – Facebook expands to allow anyone to register.

March 28, 2007 – Former Harvard classmates Cameron and Tyler Winklevoss sue Zuckerberg in federal court, alleging that he stole the idea for Facebook from them. The two sides later agree to a $65 million settlement.

May 18, 2012 – The initial public offering of Facebook stock takes place.

October 4, 2012 – Facebook reaches one billion active monthly users.

June 2013 – Leaker Edward Snowden releases documents on the NSA’s Prism program. Snowden claims that the NSA has monitored the users of Facebook and other internet companies. Zuckerberg denies Facebook cooperated with the NSA in a post.

February 19, 2014 – Facebook announces that it is purchasing mobile messaging service WhatsApp for $19 billion.

June 17, 2014 – A study by researchers at Cornell, the University of California San Francisco and Facebook is published in Proceedings of the National Academy of Science. For one week in early 2012, according to the study, Facebook changed the content mix in the news feed of approximately 690,000 users and manipulated the content to gauge the user’s emotional response. The study found that users who were shown negative content were slightly more likely to produce negative posts. Users in the positive group responded with more upbeat posts. Many users react with anger at what they say is a dangerous social experiment.

June 23, 2015 – Stock rises 3% to reach an all-time high. The company’s market value is close to $245 billion, making it worth more than Walmart, a $235 billion company.

August 24, 2015 – Facebook hits a milestone when 1 billion users log in to the social network in a single day.

September 15, 2015 – Zuckerberg announces that Facebook will be introducing a “dislike” button, so users can express sympathy for people in their network sharing sad news.

February 24, 2016 – Facebook adds “Love,” “Haha,” “Wow,” “Sad” and “Angry” reaction buttons that people can click when responding to a post.

April 27, 2016 – Shares rise almost 9% to hit an all-time high of more than $118 after the company reports first-quarter sales jumped 52% and profits were up nearly 200% compared with the first quarter of 2015.

October 30, 2016 – A ProPublica report says Facebook’s Ethnic Affinities ad-customization option can be used to discriminate against users with housing-related ads, which is forbidden under the Fair Housing Act. In the wake of the report, the company announces that it plans to disable the ethnic affinity feature on ads for housing, employment and credit.

November 15, 2016 – Facebook and Google announce they will no longer allow fake news publishers to use their ad selling services. Facebook says material from fake news publications falls under the category of “illegal, misleading or deceptive” content. Zuckerberg, however, rejects the idea that fake news on Facebook influenced the US presidential election.

April 13, 2017 – Announces that it has cracked down on 30,000 fake accounts in France ahead of the country’s presidential election. The accounts were targeted to prevent trolling, spam and hoaxes, a Facebook spokesman says.

August 3, 2017 – Rolls out a “Related Articles” feature that provides links to stories from fact checking sites such as Snopes and PolitiFact.

September 6, 2017 – The company reveals that it sold about $100,000 worth of ads during the 2016 presidential election cycle from inauthentic accounts and pages “likely operated out of Russia.”

September 14, 2017 – ProPublica reports that Facebook’s platform allows advertisers to target users who enter terms such as “jew hater” in the education or employment fields of their personal profiles. The next day, Facebook announces it removed anti-Semitic advertising categories.

September 15, 2017 – The Wall Street Journal reports that Facebook has given Special Counsel Robert Mueller records related to Russia-linked ads that were posted on the social network during the presidential campaign.

September 21, 2017 – Says it will share content and related information from more than 3,000 ads it sold to Russia-linked accounts with the House and Senate intelligence committees.

September 27, 2017 – CNN reports that at least one of the Facebook ads purchased by Russians during the 2016 presidential campaign referenced Black Lives Matter and was targeted to reach users in Baltimore and Ferguson, Missouri.

October 2, 2017 – Facebook gives Congress copies of the 3,000 political ads linked to Russia. CNN reports that some of the ads depicted refugees as rapists and others promoted gun rights. A ranking member of the House Intelligence Committee says he hopes to release a sampling of the ads to the public.

October 27, 2017 – The company announces new transparency measures including a requirement for election-related advertisements to disclose the individual or organization that paid for the post.

October 30, 2017 – CNN reports that Facebook executives will inform Congress that roughly 126 million Americans may have viewed content generated by a Kremlin-connected troll farm between June 2015 and August 2017. The next day, representatives from Facebook, Twitter and Google testify before the Senate Judiciary Subcommittee on Crime and Terrorism as legislators continue to probe Russian meddling in the 2016 election.

November 21, 2017 – ProPublica reports that it was able to buy dozens of housing advertisements targeted to audiences that excluded “African Americans, mothers of high school kids, people interested in wheelchair ramps, Jews, expats from Argentina and Spanish speakers.” The company had said that it removed discriminatory ad tools after ProPublica reported in September that the social network allowed advertisers to target users who included terms like “jew hater”in their personal profiles. A Facebook executive says that a technical glitch allowed ProPublica to purchase the ads.

January 19, 2018 – Zuckerberg announces that Facebook is surveying users to rate news organizations and assign them trust scores. The scores and other factors are going to determine how much content from each publication will appear in news feeds.

March 16, 2018 – Facebook announces that it is suspending a data firm called Strategic Communication Laboratories (SCL) and its subsidiary Cambridge Analytica, which provided the Donald Trump presidential campaign with digital voter outreach services. In a statement, the social network’s vice president and deputy general counsel says that Cambridge Analytica harvested user data through a third party app, violating the company’s policies protecting people’s information. The data was gathered by Aleksandr Kogan, a Russian-American psychology professor who built a Facebook app and got about 270,000 volunteers to take a personality quiz. The volunteers consented to share info from their profiles with Kogan for academic purposes. Kogan then turned over the data to Camridge Analytica. When Facebook learned of the violation in 2015, the company removed the app and asked Cambridge Analytica to certify that it had deleted the harvested data.

March 17, 2018 – A joint investigation by the New York Times and the Observer of London reports that Cambridge Analytica obtained data from 50 million American Facebook users via Kogan’s app. Cambridge Analytica covered the expenses of creating the app and used the info to create targeted political advertising for Trump, according to the investigation. At least some of the data was not deleted as requested by Facebook in 2015, the newspapers reported.

March 20, 2018 – A group of Facebook investors file a federal lawsuit against the company for allegedly making “materially false and misleading statements” about its privacy policies. The company’s value plunged nearly $50 billion in a Wall Street sell off triggered by the Cambridge Analytica scandal.

March 21, 2018 – During an interview on CNN, Zuckerberg says “I’m really sorry that this happened,” acknowledging that Facebook made mistakes and should have responded more robustly to secure user data. He also says that his company is prepping to combat potential meddling in the 2018 midterm elections. Earlier in the day, Zuckerberg posted a message on Facebook with a timeline of events that led to the Cambridge Analytica leak.

July 26, 2018 – Shares plunge 19% after executives warn that revenue growth would slow as the company focuses on user privacy. The sell-off vaporizes about $119 billion in market value – the biggest single-day loss for any public company in history.

July 31, 2018 – Facebook announces it has removed a network of suspected Russian-linked accounts and pages involved in organizing political events in the United States. The network is the most extensive effort to interfere in American politics that Facebook has found and made public ahead of November’s midterm elections.